The present invention refers to a winding spool for ribbonlike or filamentary material, and in particular to a winding spool of the type having a cylindrical mandrel provided at each axial end with a disk-like rim, an inner hub arranged concentrically to the center axis of the mandrel and connected to one axial end of the mandrel, and a cover secured to the other axial end of the mandrel in opposition of the inner hub.
A winding spool of this type is attached and secured to a mandrel drive shaft of a winding machine and driven at extremely high speed during winding of the material. Generally, the winding spool is attached to the mandrel drive shaft from the axial end where the cover is located, with the drive shaft only covering part of the entire width of the spool. The inner hub is of relatively short length in relation to the width of the spool so that the drive shaft will not engage the inner hub. Forces exerted during winding of material are therefor transmitted to and received solely by the cover which is thus subjected to significant stress. This excessive stress may cause a detachment of the cover from the cylindrical mandrel of the spool, leading to a loosening of the spool from the drive shaft. Eventually, the spool moves away from the shaft in an uncontrolled manner, subjecting the user to great danger.